Grouping and stacking attachment for slicing machine

ABSTRACT

An attachment for a heavy duty food slicing machine capable of either grouping or stacking slices received by the slicing machine, wherein a flipper is provided onto which the meat slices are deposited directly upon being sliced, and from which the meat slices are transferred to a station for further processing. A hydraulic drive motor operates the flipper by periodically rotating the flipper through 180* revolutions. The flipper when stationary, receives slices, and when rotating, transfers the slices to a station for further processing. The hydraulic motor is uniquely constructed to perform the drive function necessary to periodically rotate the flipper through 180* revolutions.

[ Aug. 27, 1974 United States Patent Rehlander GROUPING AND STACKING 3,587,688 6/1971 83/90 ATTACHMENT FOR SLICING MACHINE l [75] Inventor: Conn Rehlander, La Porte, Ind. Pnmary Exanuner G Abercromble Attorney, Agent, or FirmDominik, Knechtel, Godula & Demeur [73] Assignee: Land OFrost, lnc., Lansing, 111.

22 Filed: June 4, 1973 21 Appl.No.: 366,404

[57] ABSTRACT An attachment for a heavy duty food slicing machine capable of either grouping or stacking slices received by the slicing machine, wherein a flipper is provided onto which the meat slices are deposited directly upon being sliced, and from which the meat slices are transferred to a station for further processing. A hydraulic drive motor operates the flipper by periodically rotating the flipper through 180 revolutions. The flipper when stationary, receives slices, and when rotating, transfers the slices to a station for further processing. The hydraulic motor is uniquely constructed to perfonn the drive function necessary to periodically rotate the flipper through 180 revolutions.

l0 Claim, 8 Drawing Figures Related US. Application Data [63] Continuation of Ser. No. 171,183, Aug. 12, 1971.

[52] US. 83/91, 83/157 [51] Int, B26d 4/46 [58] Field of 83/86-96, 157,

[56] References Cited UNITED STATES PATENTS l,l92,0l4 7/1916 83/96 2,008,090 7/1935 Walter.............. 2,834 388 5/1958 Meyer /Z "111' film V Inventor Conn ehlander PATENTEDmzmu PATENTEB Inverzfan Conn; Remainder B I.

PATENTEnauazmn SHEET 3 Bf 3 www I v Inverfiror j cm Rehlander GROUIPING AND STACKING ATTACHMENT FOR SLICING MACHINE This is a continuation of application Serial No. 171,183, filed Aug. 12, 1971, now abandoned.

This invention relates in general to a grouping and stacking attachment especially applicable to a heavy duty food slicer of the type shown in US. Pat. No. 2,922,280, and more particularly to a slicing machine attachment capable of catching the slices coming off a slicing machine and grouping or stacking same for further processing.

In the commercial processing of foods for conversion to consumer use, foods such as loaf meats and the like are sliced, and the slices are either grouped or stacked for further processing, such as packaging same.

Grouping is usually employed where meats such as dried beef or the like are sliced extremely thin, where it is not possible or desirable to stack the slices. Heretofore, such thin sliced meats have been discharged from the slicing machine in large piles from which groups would be formed manually by hand picking slices from the piles. Such makes it difficult to obtain quick and accurate weight in the groups.

Stacking of meat slices, which are much thicker than meat slices being grouped, as they are being sliced and discharged directly from high speed, heavy duty slicers has also been difficult because the slices must be unifonnly oriented to obtain a meat stack.

The grouping and stacking attachment of the present invention overcomes the problems heretofore encountered in that sliced meats from a heavy duty slicer can be effectively handled in grouping or stacking operations for direct packaging in consumer sizes. The attachment of the invention includes a flipper rotatable on a shaft extending parallel to the slicing blade and positioned directly adjacent the slicing blade and at a level about even with the lower side of the food being sliced. The flipper is double-sided so that it may catch a group or stack of slices of a given number, rotate 180, and present a second catching surface for the subsequent group or stack of slices being discharged by the slicing knife. As the flipper rotates through a 180 revolution or cycle, it deposits the group or stack of food slices onto a conveyor or the like spaced therebelow for further handling. Accordingly, the flipper must rotate at a high speed between slicing operations so that it is not necessary to shut down the slicer during the intermittent 180 revolutions of the flipper. Movement of the flipper is synchronized with the operation of the slicing knife. In the case of the flipper which stacks slices, one side of the flipper is formed to cause straightening of the stack of slices prior todepositing same onto a conveyor to provide neater and more straight stacks of meat slices, thereby enhancing the packaging operation.

The flipper is driven by a hydraulic motor operable to rotate the flipper during each 180 revolution at a very high speed. The motor includes a vane pump selectively coupled to the flipper by means of a hydraulically actuated piston which coacts with the vane pump to synchronize the cycling of the flipper.

Accordingly, it is an object of the present invention to provide an attachment for food slicing machines capable of grouping and slicing slices received from the slicing machine.

including a double-sided flipper rotatable on an axis parallel with the cutting plane of the slicing knife and driven by a motor intermittently through revolutions to alternately present the opposite sides for re ceiving the slices from the slicing machine.

A still further object of this invention resides in the provision of a grouping and slicing attachment including a flipper movable intermittently through 180 revolutions, and a hydraulic motor for driving the flipper having a vane pump and a piston coacting to intermittently couple to the flipper to rotate same quickly through the 180 revolutions between slicing operations.

Other objects, features and advantages of the invention will be apparent from the following detailed disclo sure, taken in conjunction with the accompanying sheets of drawings, wherein like reference numerals refer to like parts, in which:

FIG. 1 is a top plan view, partly fragmentary, of the grouping and stacking attachment of the invention, with some parts broken awayto show underlying parts, and illustrating the attachment associatedwith a food slicing machine.

FIG. 2 is an end elevation view of the hydraulic motor for driving the flipper, taken substantially along line 22 of FIGS. 1 and 5.

FIG. 3 is a transverse sectional view taken through the hydraulic motor substantially along line 33 of FIGS. 1 and 5.

FIG. 4 is a transverse sectional view ofthe hydraulic motor taken substantially along line 44 of FIGS. 1 and 5.

FIG. 5 is a greatly enlarged partly sectional view of the hydraulic motor and drive train for connection to the flipper, and illustrating the motor in coupled engagement with the flipper drive train, and taken substantially along line 55 of FIG. 4.

FIG. 6 is a transverse sectional view taken through the motor substantially along line 6-6 of FIG. 5, and illustrating the vane pump portion of the motor.

FIG. 7 is a side elevational view of the attachment showing the flipper construction especially useful for stacking of slices; and

FIG. 8 is a side elevational view of a modified flipper useful for grouping of slices.

While the attachment of the invention may be mounted adjacent any food slicing machine for the purpose of receiving slices directly as they are cut by the machine to group and stack same, it is especially useful for high speed slicers in wholesale food packaging plants. Further, as an example of the type of slicer for which the invention may be used, reference is made to the above identified patent wherein the slicing machine includes a circular slicing knife eccentrically mounted on a shaft and rotatable on its own axis as it swings about the shaft into the food to be sliced, the latter of which is mounted on a food support and incrementally advanced by a pusher into the path of the slicing knife or blade. As seen in FIGS. 1 and 7, a loaf of food 10 such as meat, is incrementally advanced along a supporting surface 11 toward a slicing knife or blade '12 of a food slicing machine 13. As the knife slices the meat,

the slice is discharged away from the knife, essentially at a right angle to the cutting plane, and between slicing operations, the meat is incrementally advanced into the path of the slicing knife 12 for subsequent slicing operations.

The grouping and stacking attachment of the invention, generally designated by the numeral 15, FIGS. 1 and 7, is suitably mounted at the slicing end of the slicing machine 13, preferably directly to the machine, and generally includes a flipper 16 driven in synchronism with the slicing knife 12 by a hydraulic motor 17. The flipper is positioned to receive the slices, and is driven intermittently through 180 revolutions by the motor 17 in synchronism with the slicing knife 12 so that the flipper rotates through each 180 revolution between slicing operations of the slicing knife 12. Thus, no slices are wasted or not discharged directly onto the flipper.

The flipper takes one form when used for grouping of slices, FIG. 8, and another form when used for stacking of slices, FIG. 7.

The form employed for grouping of slices is shown in F IG. 8 wherein it includes a core or shaft 20 having a plurality of spring-like wire fingers 21 extending from opposite sides and arranged in parallel spaced relationship. The fingers are arcuate in form and each set of fingers 21 on each side of the shaft 20 will essentially present a slightly convex surface onto which the slices are discharged from the slicer for grouping. When a predetermined number of slices are received by the fingers at one side of the shaft, to present essentially a group of slices having a predetermined weight, the flipper is rotated through a 180 revolution at a high speed to discharge or transfer the group of slices onto a conveyor arranged therebelow for further processing. The conveyor will move the slices away to a station where the group of slices will then be packaged. Any type of conveyor may be employed for receiving the group of slices. It will be therefore appreciated that the fingers on the other side of the shaft will take the slicereceiving position for the next group of slices. For this reason, the fingers 21 are carried on opposite sides of the shaft in juxtaposed relation with each other so that each set of fingers when brought into generally horizontal arrangementwill present a convex slice receiving surface for the slices discharged from the slicer.

The flipper 16 will take the form shown in FIG. 7 for stacking of slices, wherein a plurality of spaced bladelike fingers 25 are mounted on and extend from oppo site sides of the core or shaft 26. The blade-like fingers are similarly arranged in parallel spaced relationship, there being whatever number needed to present a slice receiving surface of desired width. As already mentioned slices to be stacked are much thicker than slices to be grouped. Each finger 25 is provided with a slice receiving edge 27 which is formed in a generally inverted V-shape, and which includes opposed downwardly and oppositely extending edge portions 27a and 27b interconnected at their junction by an arcuate edge portion 270, the latter of which smoothly blends into edge portions 270 and 27b. The slice receiving edge terminates adjacent the knife 12 at an edge 27d which is positioned slightly above the bottom edge of the loaf 10. Accordingly, as a slice is discharged from the slicing knife 12, the lower end of the slice first engages the nearby inner edge 27d and then starts at its upper end to fall away from the blade and flop over the upper surface 27 or the lowermost slice and over the convex edge portion 27c and finally onto the outer edge portion 27a and the inner edge portion 27b. Each succeeding slice then essentially falls onto the preceding slice, thereby ultimately defining a stack of slices that are bowed upwardly in the middle by the upper surface 27 of the fingers 25. The fingers 25 essentially trip the slices as they are discharged onto the flipper, wherein the contour of the fingers function to stop the slices and cause accurate stacking.

When the flipper is loaded with a given number of slices, it is then rotated through a revolution at such a fast speed that the underside edge 28 of the other set of fingers will contact the upper surface of the topmost slice in the stack and perform a straightening operation on the entire stack before it can fall away so that when it is thereafter transferred to a conveyor it will be essentially flat and not have the upward bow in the middle.

More specifically, the lower or underside edge 28 includes an arcuate surface 280 and a straight surface 28b at the inner end. The arcuate surface has the same radius of curvature as the surface upon which the stack is deposited. The straight edge 28b functions to engage the outer edges of the slices of a'stack to straighten same if out of alignment, while the arcuate surface 28a serves to form the stack to the contour of the surface upon which it is deposited, whereby the stack hits the surface of the conveyor unifonnly across the entire surface.

In the situation of the stacking flipper, it is necessary to provide a conveyor for receiving the stacks of slices immediately below and adjacent to the flipper, to maintain the desired relative orientation between slices. A conveyor coacting with the flipper to receive the stacks is shown in FIGS. 1 and 7, and designated by the numeral 30. The conveyor 30 includes a plurality of sideby-side arranged large pulleys 31 carried on a shaft 32 and rotatable therewith, and a plurality of si'de-by-side small pulley grooves 33 formed on a shaft 34 that is parallel spaced from the shaft 32. The shafts 32 and 34 are bearingly supported on a frame 35 that may in turn be suitably connected to the slicing machine. A plurality of belts 36 are trained over the pulleys 31 and the pulley grooves 33, it being appreciated that each pulley 31 is aligned with a pulley groove 33 for supporting a belt 36, the plurality of belts serving as a supporting surface for receiving and conveying stacks of meat delivered from the flipper 16. The large pulleys 31 are equidistantly spaced apart, the spaces therebetween aligning with the fingers 25 of the flipper 16 so that upon rotation of the flipper through 180 revolutions, the ends of the flipper fingers will pass through the spaces between the pulleys and clear the shaft 32.

Stacks of meat are deposited at the inlet end of the conveyor 30 adjacent the slicing machine, at the arcuate contour of the pulleys 31 which is the same as the arcuate contour of the underside surfaces 28a of the flipper fingers 25, and then carried by the conveyor along a downwardly inclined path to a second conveyor 40 which is arranged to carry away the stacks of meat in a horizontal direction to a processing station.

The conveyor 40 is defined by a plurality of belts 41 which are trained at one end around shaft 34 in belt grooves formed on the shaft 34 between the belt grooves 33, and which are trained over a similar belt grooved shaft at a suitable spaced distance from the shaft 34. Power is supplied to the conveyors 30 and 40 through a belt drive 42 coupled to the shaft 34. I

The shaft 32 of the conveyor 30 is adjustably mounted to permit the inlet end of the conveyor to be raised or lowered toward the flipper 16 so that it can properly receive the stacked meat, and to properly tension belst 36, it being appreciated the shaft 32 is adjustable along a line on which lies the center of the shaft and the center of the arcuate finger surface 28a. The adjusted height of the belts on the pulleys 31 is such as to permit the stack to pass through under the fingers 25.

Referring now to FIGS. 1 to 6, the hydraulic motor 17 is coupled to the flipper shaft 26 through a drive train 50 which includes a housing 51. The flipper shaft 26 extends into the housing 51 and has mounted on the end thereof a bevel gear 52 supported by a bearing 53, and in meshing engagement with a bevel gear 54 carried on a driven shaft 55 which extends at right angles to the flipper shaft 26. Bearings 56 and 57 support the driven shaft 55. The hydraulic motor 17 is connected directly to the housing 51 of the drive train 50, and accordingly supported thereby. The drive motor 17 includes an oscillating vane motor 60 and a reciprocating piston motor 61. The oscillating vane motor 60 imparts rotation to the driven shaft 55 in 180 revolutions or increments, while the reciprocating piston motor 61 selectively couples the vane motor to the flipper drive train.

The vane motor 60 is in the form of a vane pump including a vane 63 oscillatable in a bore 64 and integral with an output drive shaft 65. First and second fluid chambers 66 and 67 are defined in the bore 64 by the vane 63, the enlarged portion 65a of the shaft 65, and the ends 68 and 69 of a fixed block 70, wherein the ends define stops for the vane in the opposite positions. Fluid inlet and outlet ports 71 and 72 are provided in the fixed block and communicate with ports 71a and 72a opening through the ends 68 and 69 of the fixed block 70. These ports alternately operate as inlet and outlet ports for their respective fluid chambers to drive the vane in opposite directions between the ends 68 and 69 of the fixed block 70. The port 72a further coacts with an extension 73 secured to one side of the vane 63 to dampen the movement of the vane 63 as it nears the end of its stroke towards the end 69 of the fixed block 70, the movement in this direction toward end 69 being the power stroke of the output drive shaft 65 when it is connected to the driven shaft 55 of the drive train, and therefore loaded, since the inertia of the drive train must be dampened. Accordingly, alternating fluid pressure to fluid chambers 66 and 67 will cause oscillating movement of the vane 63.

The reciprocating piston motor 61 includes a multilanded piston or spool 80, including outer lands 80a and 80d and inner lands 80b and 800, reciprocable in a cylinder or bore 81 and carried on a stem 82 that extends axially through the vane motor 60 and the output drive shaft 65 to a blade-shaped coupling member 83. The piston 80 is locked on the stem 82 against axial movement therealong, but is rotatable thereon to provide uniform wear of parts. At the right end, FIG. 5, the piston abuts against a shoulder 820, while at the left end, it is held thereon by a nut 82b. The coupling member 83 is reciprocably guidable in a slot 84 formed in the end of the output drive shaft 65 along a diameter of the drive shaft. A slot 85 is formed in the adjacent end of the driven shaft 55.along a diameter'thereof and sized to receive the coupling member 83. Thus, the reciprocating piston motor 61 alternately connects and disconnects the output drive shaft 65 and the driven shaft 55 by alternately moving the coupling member 83 into and out of engagement with the slotted driven shaft 55. As shown in FIGS. 1 and 5, the coupling member 83 is in engagement with the driven shaft 55, thereby coupling the shafts 65 and 55 together, and when the piston is in its extreme leftposition the stem 82 connecting to the bladed coupling member 83 withdraws the coupling member from the slot of the driven shaft 55 into the slot 84 to disconnect the shafts 65 and 55.

Movement of the piston motor and the vane motor is accomplished by suitable hydraulic control circuit (not shown) which would include the usual hydraulic control valves to selectively apply pressurized fluid at the opposite ends of the piston 80 and opposite sides of the vane 63 in sequence to attain the desired coupling between the shafts 65 and 55 and driving of the shaft 55 in the same direction in 180 revolutions. When engaging the coupling between the shafts 65 and 55, pressurized fluid is fed to the port 86 which is introduced into the left chamber 87 to drive the piston 80 to the extreme right in the position as illustrated in-FlG. 5. The same pressurized fluid is transferred to the vane motor port 71 through a port 88 leading from the chamber 87 into a passageway 89 that connects to the port 71 after the outer land 80a has moved beyond'the port 88. As the piston completes the stroke to the right, the space between outer land 80d and adjacent land 80c aligns with the port 92 to permit exhausting of fluid from the vane motor chamber 67 through port 72, passageway 93, port 92 to the space between the lands 80c and 80d, through a plurality of circumferentially arranged holes extending through land 80d which forces valve 101 away from the land against the force of spring 102,.into chamber 91, and out port 90. The return of the piston 80 to its left position is accomplished by applying pressurized fluid to the port 90, while connecting port86 to exhaust, which delivers the fluid into the righthand chamber 91 and causes the piston to move leftward to withdraw the coupling member 83 from the slot 85 of the driven shaft 55. At the end of the stroke for the piston, the pressurized fluid enters the passageways 92 and 93 to apply pressurizd fluid through the port 72 and into chamber 67 of the vane motor to the other side of the vane 53 and cause the vane output'drive shaft 65 to return to the position against stop 68 for the next cycle of rotation of the driven shaft 55. The chamber 66 of the vane drive and the piston chamber 87 are at the same time connected to exhaust or tank through the passageway 89, the port 88, the space between lands 80a and 80b, through a plurality of circumferentially arranged holes 103 extending through land 80a which unseats check valve 104 away from the land against the force of spring 105, into chamber 87, and out port 86. It will be appreciated check valves 101 and 104 are forced to seated position by their respective springs and the pressure of the fluid in the respective chambers during stroking of the piston.

In order to further assure that the flipper when moved through the revolutions is maintained in the proper horizontal position for receiving slices when it is decoupled from the hydraulic motor, a spring biased detent 97, mounted in the housing 51, engages in one or the other of diametrically opposed indents 98 formed in the driven shaft 55, FIG. 5. Accordingly, the flipper will not move out of position when it is disengaged from the motor.

In operation, the motor 17 will intermittently drive the flipper 16 through 180 revolutions by the selective connection of ports 86 and 90 to pressure and exhaust. Any suitable solenoid actuated control valve may be employed to alternatively apply pressurized fluid to one of the ports 86 and 90 to connect the other of the ports to exhaust. Application of pressurized fluid to port 86 first causes engagement of the output shaft 65 to the driven shaft 55 and the flipper, and thereafter the driving of the vane motor 60 to rotate the driven shaft 55 clockwise (FIG. 6) through a 180 revolution in the direction indicated by the arrow 94, FIGS, which in turn rotates the flipper in the direction of arrow 95, FIG. 7. The vane 63,-as viewed in FIG. 6, will move clockwise to the stop 69 during driving of the shaft 55. Thereafter, when pressurized fluid is admitted to port 90 and port 86 is connected to exhaust, the piston 80 is driven to the left, FIG. 5, to disengage the coupling member 83 from the slot 85 of the driven shaft 55, and following full disengagement, the pressurized fluid is then admitted to the vane motor 60 through the port 72 which is connected to the passageways 88 and 89 to drive the vane 63 against the stop 68 and place the coupling member 83 in the proper position for reinsertion in slot 85 of the driven shaft 55 for the next 180 revolution of the flipper 16. During the movement of the piston 80 leftward within the cylinder 81, damping is provided by the entry of the nut 82b into the blind bore 96 which would be full of fluid, thereby necessitating the end of the stem to force fluid out of the bore, this resulting in a cushioning action for the piston.

It will be understood that modifications and variations may be effected without departing from the scope of the novel concepts of the present invention, but is is understood that this application is to be limited only by the scope of the appended claims.

The invention is hereby claimed as follows:

1. A grouping and stacking attachment for a food slicer to receive food slices in groups or stacks as they are discharged from the slicer, wherein the food slicer includes a slicing knife and means for driving the knife and food to be sliced to make successive slices, said attachment including a two-sided flipper mounted to rotate on an axis parallel to the cutting plane of the slicing knife. said flipper including a core and a pair of slice supporting means extending from opposite sides thereof, and a hydraulic drive for intermittently cycling said flipper through 180 revolutions between slicing operations at a speed such that each of the slice supporting means is alternately presented into slice receiving position for receiving slices from the slicing machine and alternately discharges the slices received to a location therebelow.

2. The combination as defined in claim 1, wherein the flipper includes a shaft and a plurality of fingers extending from opposite sides thereof, whereby the fingers on each side define a slice supporting means.

3. The combination as defined in claim 2, wherein said fingers are arcuate and present a convex surface for receiving food slices.

4. The combination as defined in claim 2, wherein the fingers include arcuate wire members arranged in parallel spaced relation to define a convex surface for receiving the food slices.

5. The combination as defined in claim 1, wherein the flipper includes a shaft extending parallel to and ad- 5 jacent the cutting plane of the slicing knife, two sets of fingers one extending from each side of the shaft and normal thereto and defining two slice supporting surfaces, whereby each set of fingers in slice receiving position is directly adjacent the slicing knife to receive slices as they are sliced.

6. The combination as defined in claim 5, wherein each set of fingers includes a plurality of fingers arranged in parallel spaced relation, and arcuately formed to define a convex slice receiving surface.

7. The combination as defined in claim 5, wherein each set of fingers includes a plurality of blade-shaped fingers to form a relatively inverted V-shaped slice receiving surface on one side and an arcuate surface on the other side, the same as a take away slice receiving surface arranged below the fingers, whereby the V- shaped surface facilitates receiving and catching the slices in stack relationship and the arcuate surface straightens the stack by engaging the top of the stack during cycling of the flipper.

8. The combination as defined in claim I, wherein the drive includes an oscillating vane motor for transmitting power to the flipper to intermittently drive it through revolutions, and a reciprocating piston motor for coupling and decoupling the vane motor to the flipper.

9. The combination as defined in claim 1, wherein said hydraulic drive includes a driven shaft, a drive shaft, a vane motor for oscillating the drive shaft through 180 revolutions, reciprocable coupling means for coupling and decoupling the drive and driven shaft, a piston motor for reciprocating said coupling means, a first fluid port and associated passageways for the pis' ton motor and the vane motor through which pressurized fluid causes operation of'said piston motor to couple the drive and driven shafts and operation of the vane motor to rotate the shafts through a 180 revolution in a first direction, and a second fluid port and associated passageways for the piston motor and vane motor through which pressurized fluid causes operation of said piston motor to decouple the drive and driven shafts and operation of the vane motor to rotate the drive shaft through a 180 revolution in a second and opposite direction, whereby continuous operation of said drive rotates the driven shaft intermittently through 180 revolutions in one direction.

10. A grouping and stacking arrangement for a food slicer to receive food slices in groups or stacks as they are discharged from the slicer, wherein the food slicer includes a slicing knife and means for driving the knife and food to be sliced to make successive slices, said attachment including a two-sided flipper mounted to rotate on an axis parallel to the cutting plane of the slicing knife, said flipper including a core and a pair of slice supporting means extending from opposite sides thereof, and a drive for intermittently cycling said flipper through 180 revolutions between slicing operations at a speed such that each of the slice supporting means is alternately presented into slice receiving position for receiving slices from the slicing machine and alternately discharges the slices received to a location therebelow. 

1. A grouping and stacking attachment for a food slicer to receive food slices in groups or stacks as they are discharged from the slicer, wherein the food slicer includes a slicing knife and means for driving the knife and food to be sliced to make successive slices, said attachment including a two-sided flipper mounted to rotate on an axis parallel to the cutting plane of the slicing knife, said flipper including a core and a pair of slice supporting means extending from opposite sides thereof, and a hydraulic drive for intermittently cycling said flipper through 180* revolutions between slicing operations at a speed such that each of the slice supporting means is alternately presented into slice receiving position for receiving slices from the slicing machine and alternately discharges the slices received to a location therebelow.
 2. The combination as defined in claim 1, wherein the flipper includes a shaft and a plurality of fingers extending from opposite sides thereof, whereby the fingers on each side define a slice supporting means.
 3. The combination as defined in claim 2, wherein said fingers are arcuate and present a convex surface for receiving food slices.
 4. The combination as defined in claim 2, wherein the fingers include arcuate wire members arranged in parallel spaced relation to define a convex surface for receiving the food slices.
 5. The combination as defined in claim 1, wherein the flipper includes a shaft extending parallel to and adjacent the cutting plane of the slicing knife, two sets of fingers one extending from each side of the shaft and normal thereto and defining two slice supporting surfaces, whereby each set of fingers in slice receiving position is directly adjacent the slicing knife to receive slices as they are sliced.
 6. The combination as defined in claim 5, wherein each set of fingers includes a plurality of fingers arranged in parallel spaced relation, and arcuately formed to define a convex slice receiving surface.
 7. The combination as defined in claim 5, wherein each set of fingers includes a plurality of blade-shaped fingers to form a relatively inverted V-shaped slice receiving surface on one side and an arcuate surface on the other side, the same as a take away slice receiving surface arranged below the fingers, whereby the V-shaped surface facilitates receiving and catching the slices in stack relationship and the arcuate surface straightens the stack by engaging the top of the stack during cycling of the flipper.
 8. The combination as defined in claim 1, wherein the drive includes an oscillating vane motor for transmitting power to the flipper to intermittently drive it through 180* revolutions, and a reciprocating piston motor for coupling and decoupling the vane motor to the flipper.
 9. The combination as defined in claim 1, wherein said hydraulic drive includes a driven shaft, a drive shaft, a vane motor for oscillating the drive shaft through 180* revolutions, reciprocable coupling means for coupling and decoupling the drive and driven shaft, a piston motor for reciprocating said coupling means, a first fluid port and associated passageways for the piston motor and the vane motor through which pressurized fluid causes operation of said piston motor to couple the drive and driven shafts and operation of the vane motor to rotaTe the shafts through a 180* revolution in a first direction, and a second fluid port and associated passageways for the piston motor and vane motor through which pressurized fluid causes operation of said piston motor to decouple the drive and driven shafts and operation of the vane motor to rotate the drive shaft through a 180* revolution in a second and opposite direction, whereby continuous operation of said drive rotates the driven shaft intermittently through 180* revolutions in one direction.
 10. A grouping and stacking arrangement for a food slicer to receive food slices in groups or stacks as they are discharged from the slicer, wherein the food slicer includes a slicing knife and means for driving the knife and food to be sliced to make successive slices, said attachment including a two-sided flipper mounted to rotate on an axis parallel to the cutting plane of the slicing knife, said flipper including a core and a pair of slice supporting means extending from opposite sides thereof, and a drive for intermittently cycling said flipper through 180* revolutions between slicing operations at a speed such that each of the slice supporting means is alternately presented into slice receiving position for receiving slices from the slicing machine and alternately discharges the slices received to a location therebelow. 